Urinary losses of spermatozoa during ejaculation are negligible in boars

Boars that had a catheter implanted surgically in the urinary bladder (n = 10) were used to determine the magnitude of retrograde flow of spermatozoa into the urinary bladder during ejaculation (Experiments 1 and 2) and the post-ejaculatory retention of spermatozoa in the urethra (Experiment 2). The overall mean (+/- SD) total number of spermatozoa in the ejaculates of boars used in Experiments 1 and 2 was 62 +/- 25 x 10(9) and 65 +/- 33 x 10(9), respectively. The overall mean adjusted total number of spermatozoa in the post-ejaculation urine of boars was 106 +/- 537 x 10(6) in Experiment 1, and 41 +/- 242 x 10(6) in Experiment 2. The overall mean percentage of retrograde flow of spermatozoa into the urinary bladder was 0.15 +/- 0.78% for the boars used in Experiment 1, and 0.03 +/- 0.16% for boars used in Experiment 2. In Experiment 2, the overall mean percentage of urethral loss of spermatozoa was 0.45 +/- 1.02%, and the overall mean percentage of total urinary losses was 0.48 +/- 1.03%. These findings demonstrate that in boars, in contrast to bulls, rams, dogs, and cats, urinary losses of spermatozoa during ejaculation are negligible.